Cooling means for a continuous casting mold assembly

ABSTRACT

A graphite mold for use in continuous casting operations is cooled by elements mounted on the side faces and at the outlet end face of the mold. A plurality of the cooling elements are provided on the exterior of the mold to afford a variable cooling effect for the member being cast within the mold. An attachment device positively and detachably mounts the cooling elements on the graphite mold.

United States Patent Inventors Appl. No. Filed Patented AssigneePriority COOLING MEANS FOR A CONTINUOUS CASTING MOLD ASSEMBLY 5 Claims,1 Drawing Fig.

11.8. C1 164/283, 164/138 Int. Cl B2211 11/00 Field of Search 164/82,138, 273, 283, 348

: a r I I0 Primary Examiner-R. Spencer Annear Attorney-McGlew and TorenABSTRACT: A graphite mold for use in continuous casting operations iscooled by elements mounted on the side faces and at the outlet end faceof the mold. A plurality of the cooling elements are provided on theexterior of the mold to afford a variable cooling effect for the memberbeing cast within the mold. An attachment device positively anddetachably mounts the cooling elements on the graphite mold.

PATENTEB JUL 13 L9H QM PM w 7n W MOI R ATTORNEY 5 COOLING MEANSFOR ACONTINUOUS CASTING MOLD ASSEMBLY SUMMARY OF THE INVENTION In thecontinuous casting of noble metals and, especially,

when such metals are being cast in strip form, care must be exercisedthat the speed at which the strip is withdrawn from the casting mold isvaried depending on the thickness dimension and the thermal conductivityof the metal casting being formed. In many instances, uncontrolledcooling results in a casting which is in'a pasty or plastic condition asit issues from the mold or, where intense back-cooling exists within themold, the molten material solidifies close to the inlet end of thecasting mold and, as a result, cannot be withdrawn from the mold or thecasting lacks dimensional consistency. Ac-. cordingly, his not possibleto use the same molding assembly for casting materials having widelydifferent solidification points in a continuous casting operation. Inthe past, to overcome this problem, either difi'erent cooling elementsor different molds or a combination of the two was utilized forcontinuously casting molten material.

Graphite molds used in continuous casting operations are inherently softand, when alteration or adjustment was required during operation themolds often were destroyed during changeover. Further, graphite moldsare highly expensive because they must be machined to close tolerances.Moreover, graphite molds have a relatively short working life, whichoften amounts to only one working day, and as a result, the inherentlydesirable continuous casting process achieved by using graphite molds isnot as advantageous as the usual rolling processes.

Therefore, it is a primary object of the present invention to overcomethe disadvantages experienced in the use of graphite molds in the pastand to provide a suitable cooling arrangement for a graphite mold whichis adaptable for use with various casting materials.

Accordingly, the present invention is directed to a device comprised ofa multiple number of cooling elements consisting of at least one coolingelement located at the outlet end of the mold and several coolingelements located along the sides of the mold intermediate its inlet andoutlet ends. Another feature of the invention is the employment of anattachment device for positively and detachably securing the coolingelements to the graphite mold.

The positive connection of the side cooling elements to the graphitemold is accomplished by providing tapered surfaces on the graphite moldwith similarly inclined faces on the cooling elements with thejuxtaposed faces of the mold and the cooling elements being forced intocontact with one another by the connection means.

The cooling effect is achieved preferably by means of conduits or boreswithin the cooling elements throughwhich a cooling medium is circulated.The conduits or cooling medium flow passageways extend about the castingspace within the graphite mold for the length of the cooling elements.In different elements, the diameters of the passagewaysmay be varied andthe spacing from the casting space to the passageways also can be variedfor affording different cooling effects. Further, the flow coolingmediumxto the passageways can be independently supplied and regulatedwith the same or different cooling mediums being circulated throughthe'flow passageways in the individual cooling elements.

Where a plurality of cooling medium flow passageways are located in thecooling elements at theoutlet end of the continuous casting mold, oneflow passageway can contain a primary cooling medium for indirectcooling of the casting while another cooling element circulates asecondary cooling medi um for direct cooling of the casting, such as byblowing the cooling medium directly against the surface of the castingas it exits from the mold.

To afford effective regulating of the cooling of the casting as itpasses through the graphite mold, it is desirable to provide thermalseparation of the cooling elements and to construct them from differentmaterials having different thermal conductivities. By proper selectionof the materials in the cooling elements and the cooling mediumcirculated through 'their flow passageways, it is possible to achieve anexact control of the location of the solidification range of the castingas it is formed within the mold.

The various features of novelty which characterize the in vention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,its operating advantages and specific objects attained by its use,reference should be had to the accompanying drawing and descriptivematter in which there is illustrated and described a preferredembodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWING In the Drawing:

The drawing is a cross-sectional view through a continuous casting moldand cooling device embodying the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawing, agraphite mold 1 is shown having a casting space la extending from aninlet end 1b to an outlet end 1c. .Theexterior or peripheral surfaces 1dof the mold taper outwardly from the inlet to the outlet end of themold. In surface contact with the exterior surfaces 1d of the mold are apair of retaining elements 2 whose internal surfaces 2d are tapered toconform to the juxtaposed surfaces 1d of the mold.

At the outlet end 10 of the mold, a cooling device 3 is provided incontact with the end surface and the device has a passageway 3c in axialalignment with the casting space la within the mold. The cooling device3 may be formed'of one or more cooling elements.

During assembly, the graphite mold l is inserted into the I retainingelements 2 to force the tapered surfaces on each into closely fittingcontact, A yoke 4 is located on the surface of the cooling member 3spaced outwardly from the graphite mold and interconnects the retainingelements 2. Screws 5 adjustably bear on the yoke 4 and force a pressureplate 6 against the cooling device for securing it in position at theoutlet end of the graphite mold l and assure the closely fitting contactbetween the retaining elements 2, the cooling device 3, and the mold 1.

In the embodiment shown in the drawing, the cooling device 3 is formedof'two end cooling elements 3a, 3b which can'be made of metals or othersubstances having either the same or different thermal properties.Cooling medium flow passageways are provided by means of conduits 7located in the cooling element 3b and conduits 8 located in coolingelement 3a. The conduits 7 provide a primary coolant system for thecasting at the outlet end of the mold and the conduits 8 provide asecondary coolant system. As indicated in the draw ing, thecross-sectional dimension of the conduits 7 is greater than that of theconduits 8. Further, passageways 8a extend from theconduit 8 to the endof the passage 36 situated at its end opposite the outlet from thegraphite mold.

The primary coolant system affords an indirect'cooling effect on thecontinuous casting issuing from the graphite mold l, and effects arecooling and solidification of the casting; The secondary coolantsystem provides a flow of a coolingmedium, such-as an inert gas, oxygen,water and the like, which streams through the conduits 8 and passageways8i1'o'nto the surface of the casting as it issues from the passage3cthrough the cooling device 3. Due to the differences between the thermalconductivities of metals being molded in the continuous mold. Theposition of the transition point determines the most economicalwithdrawal speed for removing the casting from the mold.

in accordance with the invention, the retaining devices 2 provide acooling effect on the faces or exterior surfaces-1d of the mold and areconstructed of a plurality of cooling elements 2a, 2b, and 2c which arethermally separate. The cooling elements 2a, 2b, and 2c are preferablyformed of different materials and each contains a conduit 9 forming acoolant passageway with the diameter of the passageways. varyingbetween-the cooling elements. Moreover, due to the configuration of thegraphite mold and the structure of the cooling elements, the spacingbetween the centerline of the casting space In within the mold and theconduits 9 varies from cooling element to cooling element. The flowpassageways formed by the conduits 9 can be arranged to receive the sameor different cooling mediums and valves 10 are provided in each line forseparately or jointly shutting off the supply of the coolant medium intothe flow passageways. While the conduits 9, forming the flow passagewaysfor the cooling medium or mediums, are indicated in the drawing asextending transversely to the axis of the casting space through themold, it should be understood that the conduits also may be arranged inthe longitudinal or the diagonal direction or in a combination of thesedirections for affording the optimum cooling efiect on the castingwithin the graphite mold.

7 Depending on the properties of the metals passing through the graphitemold in the continuous casting operation, the

can be effected to maintain the transition region at the one positionwithin the graphite mold.

"We claim: l. A 'graphite mold assembly for continuous castingoperations, such as continuous strip casting, comprising a graphitesupply of cooling medium into the various flow passageways end faceproviding aN inlet to and the other end face an outletfrom the castingspace and side faces extendingbetweens'aid end'faces with said sidefaces disposed in diverging i'elation-v ship from theinlet end face tothe outlet end face, said cooling device comprising a cooling memberdisposed in contacting relationship with the outlet end face of saidmold, a retaining device having surfaces conforming to the shape of anddisposed in contacting relationship with the side faces of saidmold,-and means for providing closely fitting contact between said moldand said cooling member and retaining device, said retaining devicecomprising a plurality of separate first cooling elements each incontact with the side faces of said mold, said cooling member having apassageway therethrough in alignment with and forming a continuation ofthe casting space to said mold for conveying continuous castings fromsaid mold, said cooling member comprising a plurality of second coolingelements disposed about the passageway through said cooling member, saidfirst and second cooling elements having passageways for circulating acooling medium therethrough, and means for regulating the flow ofcooling medium through said first and second cooling elements whereby avariable cooling effect for the continuous casting processed throughsaid mold can be obtained.

2. In a graphite mold assembly, as set forth in claim 1, wherein saidmeans for providing closely fitting contact comprising a yoke mountedagainst the surface of said cooling member remote from the outlet endface of said mold, adjustable screws engaged with said yoke for varyingthe pressure exerted by said yoke on said cooling member and mold foreffecting the closely fitting contact.

' v 3. A graphite mold assembly, as set forth in claim 1, wherein thepassageways in said first cooling elements each having a differentcross-sectional area and the distance from the centerline of saidcasting space to each of the passageways being different.

4. A graphite mold assembly, as set forth in claim 1, wherein said meansfor regulating the flow of cooling medium comprising' a valve positionedin each of the passageways in said first and second cooling elements foreffecting independent regulation of the circulation of the coolingmedium through the passageways.

5. A graphite mold assembly, as set forth in claim 1, wherein

1. A graphite mold assembly for continuous casting operations, such ascontinuous strip casting, comprising a graphite mold and a multipartcooling device detachably connected to said mold, wherein theimprovement comprises said mold forming a casting space therein for thepassage of a casting therethrough, said mold having oppositely directedspaced end faces intersected by the passage therethrough with one endface providing aN inlet to and the other end face an outlet from thecasting space and side faces extending between said end faces with saidside faces disposed in diverging relationship from thE inlet end face tothe outlet end face, said cooling device comprising a cooling memberdisposed in contacting relationship with the outlet end face of saidmold, a retaining device having surfaces conforming to the shape of anddisposed in contacting relationship with the side faces of said mold,and means for providing closely fitting contact between said mold andsaid cooling member and retaining device, said retaining devicecomprising a plurality of separate first cooling elements each incontact with the side faces of said mold, said cooling member having apassageway therethrough in alignment with and forming a continuation ofthe casting space to said mold for conveying continuous castings fromsaid mold, said cooling member comprising a plurality of second coolingelements disposed about the passageway through said cooling member, saidfirst and second cooling elements having passageways for circulating acooling medium therethrough, and means for regulating the flow ofcooling medium through said first and second cooling elements whereby avariable cooling effect for the continuous casting processed throughsaid mold can be obtained.
 2. In a graphite mold assembly, as set forthin claim 1, wherein said means for providing closely fitting contactcomprising a yoke mounted against the surface of said cooling memberremote from the outlet end face of said mold, adjustable screws engagedwith said yoke for varying the pressure exerted by said yoke on saidcooling member and mold for effecting the closely fitting contact.
 3. Agraphite mold assembly, as set forth in claim 1, wherein the passagewaysin said first cooling elements each having a different cross-sectionalarea and the distance from the centerline of said casting space to eachof the passageways being different.
 4. A graphite mold assembly, as setforth in claim 1, wherein said means for regulating the flow of coolingmedium comprising a valve positioned in each of the passageways in saidfirst and second cooling elements for effecting independent regulationof the circulation of the cooling medium through the passageways.
 5. Agraphite mold assembly, as set forth in claim 1, wherein said first andsecond cooling elements are formed of materials having differentcharacteristics of thermal conductivity for varying the cooling on thecasting being processed through said mold.